Apparatus for extracting gold from solutions



Oct. 31, 1933. H c. PARKER 1,932,531

APPARATUS FOR EXTRACTING GOLD FROM SOLUTIONS Original Filed Jan. 5, 1932 Pug 9 f INT/ENTER M Er QTTURNEYS.

Patented Oct. 31, 1933 PATENT OFFICE APPARATUS FOR EXTRACTING GOLD FROM SOLUTIONS I Herschel 0. Parker, Los Angeles, Calif.

Original application January 5, 1932, Serial No. 584,821, new Patent No. 1,889,489, dated November 29, 1932. Divided and this application October 6, 1932.

3 Claims.

My invention relates to an apparatus for extracting gold from solutions.

The present application is a division of my copending Patent No. 1,889,489, granted November 29, 1932, for a process of extracting gold from solutions, in which the present apparatus is disclosed but not claimed.

Certain sections of the ocean adjacent to gold bearing coasts or to the mouths of rivers carrying gold in solution or suspension and also bays or inlets in these regions have been found to carry gold to the amount up to ten cents and even higher values per ton of water.

Another important and sometimes very rich source of gold bearing natural solutions are mine waters and the Water circulating or held in granite or other gold bearing rocks acting as reservoirs. The above source is known to be the cause of secondary enrichment of mines and by some authorities is held to be the chief factor even in the primary enrichment of mineral veins. My investigations show that it is quite possible for such solutions to carry as high a value as fifty cents in gold per ton of water. (See: Data of Geochemistry; F. W. Clarke, Bul. 695, U. S. G. S. p. 120; and Science, Oct. 1'7, 1924, Extraction of Gold from Seawater, Fritz Haber, University of Berlin.) j

Since the above mentioned and other sources are practically unlimited, the importance of a practical process for recovering the gold from such solutions which will yield a profit in operation is self-evident. Attempts have been made from time to time to devise processes for recovering the gold from such solutions and While it has been demonstrated that the gold can actually be recovered, all such attempts have been failures from a practical point of View for the reason that the cost of recovering the gold exceededthe value of the gold recovered. It is obvious that any process of extracting gold from solutions lacks utility unless it shows a profit in operation. The

problem, therefore, has been to devise some process which will handle relatively enormous quantities of the gold bearing water with a minimum cost of operation, which process will extract efiiciently a large or major portion of the gold contained in the water.

It is known in the art that certain materials, so called adsorbents, have the property when in contact with gold bearing Water to extract the gold from the Water and it has been proposed to cause the gold bearing water to pass through a filter composed of or containing such adsorbentsbut such attempts have been failures Serial No. 636,557

Prof.

system of substantially continuous operation 1 whereby large quantities of gold bearing water are passed rapidly through an apparatus in which it is agitated in contact with a particular adsorbent that I have discovered to be far superior to the ordinary adsorbents used, namely ferrous sulphide, and after the adsorbent has been sufiiciently enriched With' gold extracted from the water it is removed from the apparatus and the gold is recovered in any of the Well known or preferred methods.

My invention consists in the construction and combination of parts for an apparatus for carrying out the above process as hereinafter described and claimed.

In the accompanying drawing, which forms a part of the specification, Ihave illustrated a preferred embodiment for such an apparatus, and in which: 7

Fig. 1 is a vertical section of an apparatus for carrying outmy process.

Fig.2 is a horizontal section on the lines 2-2 of Fig. 1. g

Referring to the drawing, 1 indicates a pump pumping gold bearing-Water such as sea water through pipe 2 into a mixing tank 3, shown in this instance as a cylindrical vertical tank, in which a stirrer shaft 4 driven by any suitable power, not shown, is suitably journaled and is provided with stirrer arms 5. The adsorbent is supplied to the tank from acontainer 6 feeding the'adsorbent through a chute "7 provided with shut off valves 8 and 9. a The tank 3 has its bottom 3 hopper shaped and provides an outlet for the enriched adsorbentwhich preferably consists of a trap 10 with shut off valves 11 and 12. An outlet 13 for the sea water is provided with a shut oii valve 14. The conduit 13 has mounted therein a series of downwardly inclined baffle plates 15 which serve to prevent the adsorbent from passing through the outlet 13. is carried past the baflie plates 15 is stopped by a 200 mesh screen 16 at the upper endof the outlet 13. The water then passes through a pipe 1'7 into a comparatively large settling tank 18 provided with an overflow 19. bent which may have escaped through the screen 16 will settle to the bottom of the settling tank 18. The bottom of the tank 18 is hopper shaped as at Any adsorbent that I Small quantities of adsortaining what may be'called the highest point of 18' and provided with an outlet trap 20 controlled. by valves 21 and 22.

Operation.-The gold bearing water, such as sea water, is pumped into the mixing tank 3 and the adsorbent, ferrous sulphide, is admitted to the tank from the container 6 by the operation of valves 8 and 9 as will be understood. Five pounds or more of the ferrous sulphide is used per ton of water in the container 3. The ferrous sulphide should be granular in form and the granules of a size to pass between screens of 120 to 200 mesh. The stirrer shaft 4 is vigorously agitated so as to cause an intimate contact of the particles of the adsorbent material with all parts of the water passing upwardly through the tank 3.-- The water will continuously pass through the outlet 13, the adsorbent being prevented from passing out therethrough by means of baflie plates 15 and particles that may have passed the bafile plates are retained by the mesh-screen 16. Any smaller particles that may have become disintegrated and passing through the screen 16 will settle in the settling tank 18 whence the sediment may be removed periodically through the outlet 20. In order that the screen 16 may be cleaned periodically without interruption of the operation of the system, I prefer to provide outlets 13 with baiile plates, valve and screen, in duplicate as shown in Figure 2. The gold enriched ferrous sulphide is periodically removed through the outlet 10. It is merely necessary to stop the operation of the pump and the stirrer shaft for a short time to givev the ferrous sulphide an opportunity to settle. Except for this slight interruption, it will be noted that the process is a continuous one.

It. is not absolutely necessary to provide a settling tank 18, although it is the preferred construction, for the cost of the installation of the settling tank would soon pay for itself by any gold recovered which may be carried over from the mixing tank 3 to the settling tank 18.

The ferrous sulphide retains its adsorbent properties for a considerable length of time until it is enriched up to say fifty percent (50%) of its weight. My experiments have shown that it is feasible to extract as much as ninety percent of the gold contained in the water but it willbe understood that the success of this process does not dependupon the complete or nearly complete extraction of gold from the water but 'on mainthe economic operation. It may be more profitable-to pass say three times as much water through the apparatus in a given time although in the -.first instance where only one volume of water 7 is treated the extraction may be as high as eighty percent and in the other where three times the volume of water is treated it may be as low as fifty percent and the gold recovered will be in the .ratio of 8 to 15 parts of gold for a unit of time.

While the cost of treating three volumes of water it, of course, more than that of one volume, the additional cost is negligible in comparison with the increased amount of gold recovered. In the example the gold recovered would be as 15 to 8.

It will be appreciated that the process to be profitable must be carried on on a large scale requiring a great outlay of capital and that relatively enormous quantities of water must be treated and the success of the process will depend on operating the system at the point of maximum efficiency having regard to the amount of gold recovered and the cost of operation inclusive of capital investment, maintenance, taxes and the like.

Various changes in the construction and arrangement of-parts may be made by those skilled in the art without departing from the spirit of my invention as. claimed.

I claim:

1. In an apparatus of the class described, the combination of a mixing tank having a closed top and a valve controlled outlet at the bottom,

means to introduce a liquid under pressure to the mixing. tank near the lower end thereof,-

means to agitate the liquid in the mixing tank, a valve controlled container for introducing a reagent to the mixing tank, a settling tank, a conduit leading from the upper end of the mixing tank to the settling tank, and a flow retarding and screening means in the conduit.

2. In an apparatus of the class described, the

combination of a cylindrical mixing tank closed at the top and having a conical bottom providedwith a valve controlled outlet, means to introduce a liquid under pressure to the mixing tank near the lower end thereof, agitating meansin themixing tank, a valve controlled container for introducing a reagent to the mixingtank, a

lower valves, means to introduce a liquid under pressure to the mixing tank near the lower end thereof, agitating means in the mixing tank, a valve controlled container for introducing a reagent to the mixing tank, a settling tank having a conical bottom and a valve controlled outlet therein, a conduit leading from the upper end of the mixing tank to the settling tank, and a flow retarding and screening means in the conduit comprising a screen and a series of baffle plates.

I-IERSCHEL C. PARKER. 

